Fructose-1, 6-bisphosphate Couples Glycolytic Flux to Activation of Ras

Peeters K, et al. , 8(1):922, Nat Commun., 2017

Both yeast and mammalian cells share Ras, a key regulator of cell proliferation and a prime proto-oncogene product. It is known that yeast and mammalian cancer cells favor fermentation of sugar over respiration. It remains divisive whether high fermentative activity is a cause or a symptom of a cancerous state since no direct relationship between glycolysis and proteins controlling cell proliferation has been reported. Described herein is the use of the yeast tps1Δ mutant to identify the molecular link between glucose fermentation and activation of Ras. Results demonstrate that fructose-1,6-bisphosphate (Fru1,6bisP) triggers activation of Ras proteins via its Cdc25/Sos1 guanine nucleotide exchange factor. The disruption of the H-Ras/Sos1 complex by Fru1,6bisP was studied by Bio-Layer Interferometry (BLI) using a Pall ForteBio Octet RED96 instrument equipped with Ni-NTA (NTA)Biosensor probes. Biosensor tips were first loaded with HIS-tagged H-Ras followed by Sos1. Subsequently, biosensors were immersed in wells containing increasing concentrations of Fru1,6bisP and dissociation of the H-Ras/Sos1 complex was studied. The equilibrium dissociation constant (KD) was determined by plotting a titration curve and fitting it to a Langmuir equation. Similar protocols were followed to investigate the effect of Fru6P, DHAP, GAP and glucose on the H-Ras/Sos1 complex. Overall findings of this study suggest that Fru1,6bisP activation of Ras lead to enhanced fermentation rate that stimulate oncogenic potency.

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